Origin of Kayasth :- According to the Hindu scriptures known as the Purans & Vedas Kayasth are decended from Chitra gupta Maharaj. There are lots of fact of Kayasthas. There is a lots of story about the kayastha and Kayasth Pariwar in Hindu scriptures.
Let's start from the beginning of the story about the universe and the GOD.
A glimpse of origination of Universe in short :-
According to the Puran's and Vedas all the god and goddess generated at the time of sea brainstorm. Lord Brahma distributed the work and all the Power what ever they had need according to there work. Once a day Lord Brahma thought that something is missing in this Universe so they creates a living animal on the earth and also creates complementary for balancing the environment of the universe. On the earth, Man is a so much power full animal because they are wise and having mind with the power to control all the species of this earth. According to the Vedas and Purans there were four types of varna's at the initial time named: - Brahaman, Kshatriya, Vaishya, and Shudra. The meaning of Brahman is who has knowledge about the Brahma and the main work is to be active in worship of Lord. Kshatriya is known as to keep the Shastra. Vaishya is known as to spread the business. Shudra is also known as to take care and serve the people.
Kayasth as an assistant of Yamaraj:-
Yamaraj, the lord of death, requested Brahma to help him to keep the record the deeds, both good and evil, of men and to administer justice. Once a day Brahma ji thought that there is no any varnas who will keep the record the deeds, both good and evil activity that is going to be in the future on this earth. So, for the invention of book keeper the Lord Brahma Ji went to the Meditation. Chitragupta is seventeenth creation of Lord Brahma.
After 11000 years a Lord born from the body of Brahma ji. That Lord regards and asked to the Brahma ji, Now what’s the obey for me! Then Brahma ji asked. when he opened his eyes he saw a man holding a pen and ink-pot in his hands, as well as a sword girdled to his waist. Brahma ji asked, who are you and from where you come to me. Param pita Brahma spoke:
Thou hast been created from my body (kaya); therefore, shall thy progeny be known as the Kayasthas. Thou hast been conceived in my mind (chitra) and in secrecy (gupta); thy name shall also be Chitragupta.Brahma then provided him the newly-named Chitragupta to distribute justice and punish those who violated dharma (law):
Oh son, having obtained my positive commands, thou shall be posted forever in the kingdom of Dharmaraja for the partiality of virtue and vice! Let the religious duties determined for the Kshatriya caste be followed by the according to rule.
By some accounts this is true story about the origion of kayasth, like Bhavishya Puran, Garur Puran, Sakand Puran, Devi Puran, Brihat Brahma khand written by Kamalakar Bhatt etc. Kayastha is traditionally denoted members of the writer caste. According to the Hindu scriptures known as the Puranas and Vedas, Kayasthas are embodied from King Chitragupta.whose main task is to recording the deeds of humanity, upholding justice and the rule of law and judging whether human beings go to heaven or hell after death.
Chitrgupta's family and his Genealogy:-
According to the Bhavishya puran, Padam puran and etc Brahman’s were worshiping of Lord Chitra Gupta. once upon a time Rishi Dharma Sharma went to the Lord Brahma ji with the wedding proposal of his daughter with Lord Chitra Gupta. Such as also Lord Surya’s son Manu went to the Lord Brahma ji with the wedding Proposal of his Daughter Sudakshina with Chitra Gupta. Lord Brahma become agree to marriage. After the marriage Rishi Dharm Sharma’s daughter Irawati borne Eight sons and Lord sharadh dev’s daughter Sudakshina borne Four sons. That is the starting Point of Kayasth Pariwar.